Tyre having improved wear properties

Abstract

The invention relates to a tyre comprising a crown reinforcement (4) formed by at least two working crown layers (41, 43) of reinforcing elements and at least one layer of circumferential reinforcingelements (43). According to the invention, the tread has at least one notch consisting of at least two portions, the ratio of the measured width at the bottom of the first portion (9) to the measuredwidth of said at least one first portion at the surface of the tread on a new tyre being strictly greater than 2 and the ratio of the measured width of the second portion (8) at the surface of the tread on a new tyre to the measured width at the bottom of said at least one second portion being greater than or equal to 1.

Description

Technical field

[0001] The present invention relates to tires with radial carcass reinforcements, and more particularly to tires that are intended to be equipped with heavy-duty load-carrying vehicles (such as trucks, tractors, trailers or buses) running at sustained speeds. Background technique

[0002] In heavy-duty tires, the carcass reinforcement is usually anchored on either side of the bead area, and is covered in the radial direction by a crown reinforcement composed of at least two superimposed layers, the at least two superimposed layers The layers are formed of threads or cords that are parallel in each layer and cross from one layer to the next so as to form an angle between 10° and 45° with the circumferential direction. The working layer forming the working reinforcement may be further covered by at least one layer called a protective layer, said layer being formed by reinforcing elements, which are advantageously metallic and stretchable and are called elastic Rein...

Examples

Embodiment Construction

[0100] in figure 1 Among them, the tire 1 with a size of 315 / 70R 22.5 has an aspect ratio H / S equal to 0.70, H is the height of the tire 1 on its mounting rim, and S is its maximum axial width. The tire 1 includes a radial carcass reinforcement 2 anchored in two beads (not shown in the figure). The carcass reinforcement is formed of a single layer of metal cords. The carcass reinforcement 2 is wrapped by a crown reinforcement 4, which is formed from the inside to the outside in the radial direction by the following parts:

[0101] -A first working layer 41 formed of unwrapped 9.28 non-stretchable metal cords that are continuous over the entire width of the ply and oriented at an angle of 24°,

[0102] -A layer 42 of circumferential reinforcing elements formed by 21x23 steel metal cords of the "dual modulus" type,

[0103] -A second working layer 43 formed of unwrapped 9.28 non-stretchable metal cords that are continuous over the entire width of the ply and oriented at an angle equ...

Technical field

[0001] The present invention relates to tires with radial carcass reinforcements, and more particularly to tires that are intended to be equipped with heavy-duty load-carrying vehicles (such as trucks, tractors, trailers or buses) running at sustained speeds. Background technique

[0002] In heavy-duty tires, the carcass reinforcement is usually anchored on either side of the bead area, and is covered in the radial direction by a crown reinforcement composed of at least two superimposed layers, the at least two superimposed layers The layers are formed of threads or cords that are parallel in each layer and cross from one layer to the next so as to form an angle between 10° and 45° with the circumferential direction. The working layer forming the working reinforcement may be further covered by at least one layer called a protective layer, said layer being formed by reinforcing elements, which are advantageously metallic and stretchable and are called elastic Rein...

Examples

Embodiment Construction

[0100] in figure 1 Among them, the tire 1 with a size of 315 / 70R 22.5 has an aspect ratio H / S equal to 0.70, H is the height of the tire 1 on its mounting rim, and S is its maximum axial width. The tire 1 includes a radial carcass reinforcement 2 anchored in two beads (not shown in the figure). The carcass reinforcement is formed of a single layer of metal cords. The carcass reinforcement 2 is wrapped by a crown reinforcement 4, which is formed from the inside to the outside in the radial direction by the following parts:

[0101] -A first working layer 41 formed of unwrapped 9.28 non-stretchable metal cords that are continuous over the entire width of the ply and oriented at an angle of 24°,

[0102] -A layer 42 of circumferential reinforcing elements formed by 21x23 steel metal cords of the "dual modulus" type,

[0103] -A second working layer 43 formed of unwrapped 9.28 non-stretchable metal cords that are continuous over the entire width of the ply and oriented at an angle equ...

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